Imagine the Universe!
Imagine Home  |   Ask an Astrophysicist  |  
Ask an Astrophysicist

The Question

(Submitted May 05, 1997)

I'd like to find a list of visible satellites in the evening sky. I understand that there may be many, but I'm certain that several obvious ones would be noticeable.

The Answer

From any point on Earth, there are many visible satellites that pass over each night. Which satellites are visible, and when and where they appear, has to be calculated knowing the date and the location of the observer.

There are programs available to do these calculations, such as OrbiTrack for the Macintosh. Go to your favorite shareware and public domain site (e.g. www.shareware.com) and search for 'satellite'.

You will also need a list of current satellite 'elements' which describe the orbits of each satellite. These are provided by T. S. Kelso at http://celestrak.com/NORAD/elements/ The file tle.new has the most recent elements available, while the data for the Mir space station is in mir.tle . (tle stands for 'two line elements', because all the data for a satellite is written on two lines.)

With a program and a fresh data file (they lose accuracy after a few weeks) you can get a list of visible satellite passes in your area.

David Palmer
for Ask an Astrophysicist

Questions on this topic are no longer responded to by the "Ask an Astrophysicist" service. See http://imagine.gsfc.nasa.gov/docs/ask_astro/ask_an_astronomer.html for help on other astronomy Q&A services.

Previous question
Prev
Main topic
Main

If words seem to be missing from the articles, please read this.

Imagine the Universe! is a service of the High Energy Astrophysics Science Archive Research Center (HEASARC), Dr. Alan Smale (Director), within the Astrophysics Science Division (ASD) at NASA's Goddard Space Flight Center.

The Imagine Team
Project Leader: Dr. Barbara Mattson
Curator: Meredith Gibb
Responsible NASA Official: Phil Newman
All material on this site has been created and updated between 1997-2014.
This page last updated: Thursday, 11-Jan-2007 15:04:58 EST